Heart failure is an abnormality in cardiac function that results from the inability of the heart to pump blood commensurate with the body's needs. Failure develops from a depression in myocardial contractility which can occur due to ischemic heart disease, hypertension, non-obtrusive cardiomyopathies and certain types of congenital heart disease.
As used herein, a cardiotonic agent is a substance which increases the force of contraction of heart muscle of a mammal to which it is administered. It is advantageous to achieve such increased cardiac contractile force with little or no increase in the rate of heartbeat of the mammal.
Certain N-hydroxy-5-phenyl-2-furancarboximidamides are known and have been disclosed to have antidepressant activity. U.S. Pat. No. 3,946,049 issued to Pelosi on Mar. 23, 1976, discloses certain N-hydroxy-5-phenyl-2-furancarboximidamides and methods of synthesizing them and is hereby incorporated by reference.
References which disclose compounds having structures similar to the N-hydroxy-5-phenyl-2-furancarboximidamides of the present invention includes the following U.S. Pat. Nos.: 4,012,414 issued to Pelosi on Mar. 15, 1977; 4,012,415 issued to Pelosi & Yu on Mar. 15, 1977; 4,012,416 issued on Pelosi on Mar. 15, 1977; 4,021,444 issued to Pelosi on May 3, 1977; and 4,022,798 issued to Pelosi on May 10, 1977.
References which disclose certain cardiotonic agents include the following U.S. Pat. Nos.: 3,985,891 issued to Kutter, Austel & Diederen on Oct. 12, 1976; 4,004,012 issued to Lesher & Opalka on Jan. 18, 1977; 4,032,575 issued to Ikezaki, Ito, Okazaki, Hoshiyama, Nagao & Nakajima on June 28, 1977; 4,289,772 issued to Campbell, Danilewicz, Evans & Ham on Sept. 15, 1981; 4,297,360 issued to Lesher, Opalka & Page on Oct. 27, 1981; 4,397,854 issued to Sircar on Aug. 9, 1983; 4,405,635 issued to Schnettler, Dage & Grisar on Sept. 20, 1983; and 4,705,782 issued to Logan, Redpath & Roy on Nov. 10, 1987; and European patent applications of Akzo N. V.: 0,158,380 published Oct. 16, 1985, and 0,199,393 published Oct. 29, 1986.
It is an object of the present invention to provide a method of increasing the contractile force of cardiac muscle of a mammal.
It is also an object of this invention to provide novel compounds which increase the contractile force of cardiac muscle of a mammal.
It is also an object of this invention to provide pharmaceutical compositions which increase the contractile force of cardiac muscle of a mammal.